SkPaint::FilterLevel -> SkFilterQuality

clone (+rebase) of https://codereview.chromium.org/1009183002/

BUG=skia:
TBR=scroggo@google.com

Review URL: https://codereview.chromium.org/1014533004
diff --git a/gm/giantbitmap.cpp b/gm/giantbitmap.cpp
index 2ac952d..bb9a655 100644
--- a/gm/giantbitmap.cpp
+++ b/gm/giantbitmap.cpp
@@ -109,7 +109,7 @@
         SkShader* s = SkShader::CreateBitmapShader(getBitmap(), fMode, fMode, &m);
 
         paint.setShader(s)->unref();
-        paint.setFilterLevel(fDoFilter ? SkPaint::kLow_FilterLevel : SkPaint::kNone_FilterLevel);
+        paint.setFilterQuality(fDoFilter ? kLow_SkFilterQuality : kNone_SkFilterQuality);
 
         canvas->translate(SkIntToScalar(50), SkIntToScalar(50));